mirror of
https://github.com/langchain-ai/langgraph.git
synced 2026-08-17 21:25:46 +02:00
Nuno Campos
5c2afc9418
- checkpoints are now copied before being mutated - compiled graph and compiled state graph no longer need to override get_state/update_state - pregel class now natively supports interrupt before/after
20 lines
780 B
Python
20 lines
780 B
Python
from langchain_core.pydantic_v1 import Field
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from langgraph.checkpoint.base import Checkpoint, CheckpointAt, copy_checkpoint
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from langgraph.checkpoint.memory import MemorySaver
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class MemorySaverAssertImmutable(MemorySaver):
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storage_for_copies: dict[str, Checkpoint] = Field(default_factory=dict)
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at = CheckpointAt.END_OF_STEP
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def put(self, config: dict, checkpoint: dict) -> None:
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# assert checkpoint hasn't been modified since last written
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thread_id = config["configurable"]["thread_id"]
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if saved := super().get(config):
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assert self.storage_for_copies[thread_id] == saved
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self.storage_for_copies[thread_id] = copy_checkpoint(checkpoint)
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# call super to write checkpoint
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super().put(config, checkpoint)
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